Magnetic disc pack loading mechanism

ABSTRACT

A magnetic disc pack loading mechanism used in a magnetic recording/reproducing apparatus in an electronic still camera or the like is disclosed which power loads a magnetic disc pack in a predetermined recording or reproducing position by moving a pack holder containing the magnetic disc pack therein. The loading mechanism is provided with a pre-lock mechanism which can secure provisionally the magnetic disc pack within the pack holder when the magnetic disc pack has been inserted into the pack holder and a shutter opening/closing mechanism which can open fully a shutter in the magnetic disc pack cooperatively with the loading operation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnetic disc pack loading mechanismand, in particular, to a mechanism for loading a magnetic disc packcontaining therein a magnetic disc in which still image information orthe like can be magnetically recorded.

2. Description of the Related Art

Recently, there has been developed an electronic still camera system inwhich an image pickup device such as a solid image pickup element, animage pickup tube or the like is combined with a recording deviceemploying as a recording medium thereof an inexpensive magnetic dischaving a relatively larger storage capacity such that an object can bestill photographed electronically and recorded into a rotating magneticdisc and the reproduction of the recorded image can be performed bymeans of a television system, a printer or the like which is providedseparately from the electronic still camera system.

The magnetic disc that is employed in such camera system is usually usedin the form of a magnetci disc pack. That is, in such magnetic discpack, there is stored a magnetic disc in a rotatable manner which iscapable of magnetic recording of still image information or the like,this magnetic disc pack is mounted to a magnetic recording deviceincorporated in an electronic camera or to a reproducing device arrangedintegrally with or separately from the magnetic recording device beforeit is used.

The mounting of the above-mentioned magnetic disc pack is generallycarried out by moving a pack holder in which the magnetic disc pack isstored.

Also, this type of magnetic disc pack is provided with a shutter whichis used to protect the magnetic disc against dust or the like exceptduring the recording/reproducing operation. And, this shutter can beopened by a shutter openign/closing mechanismm provided usually in theside portion of the pack holder when the magnetic disc pack is insertedinto the pack holder, and can be closed when the magnetic disc pack isdischarged out from the pack holder.

By the way, there are two types of pack holders: that is, one is a hingetype of pack holder; and, the other is slot-in type of pack holder. Thepack holder of a slot-in type is used when the magnetic disc pack ispower loaded and is generally provided with a pop-up mechanism which isused to push out the magnetic disc pack from the pack holder in anunloading operation.

Conventionally, when the magnetic disc pack is mounted by use of thepack holer of such slot-in type, an operator must continue to push themagnetic disc pack by hand until the magnetic disc pack is inserted intothe pack holder, a loading operation by the pack holder is initiated andthe pop-up mechanism for pushing out the magnetic disc pack is locked,which is very troublesome (Japanese Patent Application No. 60-284574).

Also, the slot-in type of pack holder is equipped with an insertionopening which is used to insert the magnetic disc pack into the packholder and which is also provided with an inwardly open, inner cover.There is a problem, however, that the inner cover interferes with theabove-mentioned shutter opening/closing mechanism. In order to preventsuch interference, it is necessary to provide the shutteropening/closing mechanism in the depth direction of the pack holder. Inthis case, in order to open fully the shutter of the magnetic disc pack,the magnetic disc pack must pushed in very deeply, that is, it must bepushed in until the following end thereof is moved more deeply than aninsertion opening in a front panel. It is impossible to carry out suchinsertion of the magnetic disc pack by hand.

SUMMARY OF THE INVENTION

The present invention aims at eliminating the drawbacks found in theabove-mentioned prior art devices.

Accordingly, it is an object of the invention to provide a magnetic discpack loading mechanism which is capable of provisionally securing amagnetic disc pack within a pack holder when the magnetic disc pack isinserted into the pack holder in a given amount of insertion.

It is another object of the invention to provide a magnetic disc packloading mechanism which allows a shutter provided in the magnetic discpack to be opened or closed in a position as deep as possible from aninsertion opening so as to be able to secure space for prevention ofinterference between an inner cover and a shutter opening/closingmechanism.

According to one aspect of the present invention, there is provided amagnetic disc pack loading mechanism which is adapted to position amagnetic disc pack in a recording or reproducing position by moving apack holder containing therein the magnetic disc pack in the samedirection with the insertion direction of the magnetic disc pack andthen moving the pack holder in the longitudinal direction of a rotarydrive shaft perpendicular to the above-mentioned magnetic disc packinsertion direction, wherein there is provided in the pack holder apop-up member which is free to advance or retreat, is provided in theleading end thereof with an engagement portion positioned in aninsertion area for the magnetic disc pack withing the pack holder, andis energized by a spring in a direction to discharge the magnetic discpack; there is provided in the pack holder a pre-lock lever which isfree to rotate and is energized by a spring in a direction where anengagement portion provided in the leading end of the pre-lock lever canbe brought into engagement with the magnetic disc pack; and, there isprovided a cam mechanism between the above-mentioned pop-up member andpre-lock lever. In other words, if the magnetic disc pack is insertedinto the pack holder against the return force of the pop-up member toadvance the pop-up member a given distance, then the pre-lock lever isrotated by the cam mechanism interposed between the pop-up member andthe pre-lock lever and the magnetic disc pack is provisionally securedwithin the pack holder by the rotational movements of the pre-locklever. Also, during this operation, the pop-up member is being locked bythe cam mechanism so that the pop-up member is prevented from returningto its original position.

Also, according to another aspect of the invention, there is provided amagnetic disc pack loading mechanism which is adapted to position amagnetic disc pack in recording or reproducing position by moving a packholder containing therein the magnetic disc pack in the same directionwith the insertion direction of the magnetic disc pack and then movingthe pack holder in the longitudinal direction of a rotary drive shaftperpendicular to the above-mentioned magnetic disc pack insertiondirection, wherein there is provided a slide plate movable together withthe pack holder only in the above-mentioned rotary drive shaft directionwhen the magnetic disc pack is positioned, and wherein in the slideplate there are provided a shutter opening member a portion of which canbe projected into an insertion area for the magnetic disc pack withinthe pack holder to remove the locking of a shutter in the magnetic discpack, and a shutter closing member provided with a claw engageable witha bore formed in the side surface of the shutter, the claw being adaptedto be able to project resiliently into the above-mentioned magnetic discpack insertion area. In other words, if the magnetic disc pack isinserted into the pack holder, then the shutter of the magnetic discpack climbs over the claw of the shutter closing member and is thenbrought into contact with the shutter opening memeber to thereby removethe locking of the shutter. Then, the claw provided in the shutterclosing member is brought into engagement with the bore formed in theshutter side surface. And, if the magnetic disc pack is inserted to agiven position where it can be inserted by hand, needed then the shuttercan be opened little by little along with such insertion, but, in thisposition, the shutter is not yet opened fully. After then, if a loadingoperation is performed by the pack holder in the same direction with themagnetic disc pack insertion direction, then, as the pack holder ismoved, the shutter is again opened to its fully open state.Successively, when the pack holder is moved in a direction perpendicularto the above-mentioned insertion direction, then the shutter opening andclosing members provided in the slide plate are moved to follow afterthe pack holder. On the other hand, when the magnetic disc pack is takenout from the pack holder, the shutter is at first closed by the shutterclosing member a given amount due to the movement of the pack holder inthe pack holder discharge direction, and if the magnetic disc pack isdrawn further, then the shutter is closed until it is locked by theshutter closing member.

BRIEF DESCRIPTION OF THE DRAWINGS

The exact nature of this invention, as well as other objects andadvantages thereof, will be readily apparent from consideration of thefollowing specification relating to the accompanying drawings, in whichlike reference characters designate the same or similar parts throughoutthe figures thereof and wherein:

FIG. 1 is an exploded, perspective view to show the whole structure of amagnetic recording/reproducing apparatus in which an embodiment of amagnetic disc pack loading mechanism according to the invention isemployed;

FIG. 2(a) is a front view of an embodiment of a pre-lock mechanism for amagnetic disc pack, illustrating a state of the pre-lock mechanismbefore the magnetic disc pack is pre-locked;

FIG. 2(b) is a section view taken along the line A--A in FIG. 2(a);

FIG. 3(a)is a front view of the above-mentioned pre-lock mechanism,illustrating a state thereof after the magnetic disc pack is pre-locked;

FIG. 3(b) is a plan view of FIG. 3(a);

FIG. 4(a) is a front view of the pre-lock mechanism, illustrating astate thereof in which the pre-lock mechanism is advanced together withthe magnetic disc pack after the magnetic disc pack is pre-locked;

FIG. 4(b) is a plan view of FIG. 4(a);

FIG. 5(a) is a front view of the pre-lock mechanism illustrating a statethereof in which the pre-lock mechanism is further advanced and is thenlowered down together with the pre-locked magnetic disc pack;

FIG. 5(b) is a plan view of FIG. 5(a);

FIG. 6(a) is a front view of the pre-lock mechanism illustrating a statethereof in which the pre-locking of the magnetic disc pack is beingremoved;

FIG. 6(b) is a section view taken along the line A--A in FIG. 6(a);

FIG. 7(a) is a front view of the pre-lock mechanism illustrating a statethereof in which after removal of the pre-locking of the magnetic discpack the pre-lock mechanism is further retreated together with themagnetic disc pack;

FIG. 7(b) is a section view taken along the line A--A in FIG. 7(a);

FIGS. 8(a), (b) and (c) are respectively views, illustrating therespective operational relationships between the pack holder and ashutter opening/closing mechanism;

FIGS. 9 through 14 are respectively explanatory views used to explainthe operation of the shutter opening/closing mechanism;

FIG. 15 is a view to illustrate a mechanism for opening or closing acover;

FIG. 16 is a plan view of the magnetic disc pack used in the illustratedembodiment of the invention;

FIG. 17 is a section view of the magnetic disc pack taken along the lineA--A in FIG. 16;

FIG. 18 is a perspective view of a shutter employed in the illustratedembodiment of the invention; and,

FIG. 19 is a view to illustrate the said end of the magnetic disc packemployed in the illutrated embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Detailed description will hereunder be given of the preferred embodimentof a mechanism for loading a magnetic disc pack according to the presentinvention with reference to the accompanying drawings.

At first, description will be given of magnetic disc pack which is usedin a magnetic recording or reproducing apparatus in an electronic cameraor the like. In FIG. 16, there is shown a plan view of theabove-mentioned magnetic disc pack designated by 10 and, in FIG. 17,there is shown a section view thereof taken along the line A--A in FIG.16.

As shown in FIG. 16, the magnetic disc pack 10 is constructed in asubstantially square shape and within the magnetic disc pack 10 there isstored a magnetic disc 12 in a freely rotatable manner in which stillimage information or the like can be recorded. In the central portion ofthe magnetic disc there is provided as a reinforcing member a centercore 14 which is exposed externally from an annularlyshaped opening 16formed in the magnetic disc pack 10. The center core 14 is formed with acentral bore 15 and the central bore 15 is in turn provided with aresilient piece 17. The central bore 15 in the center core 14 can befitted over a drive shaft 104 to be described later against theenergization force of the resilient piece 17.

Also, the magnetic disc pack 10 is formed with a window portion 18 inwhich a magnetic head to be described later is positioned and the windowportion 18 can be opened or closed by a slidable shutter 20. In otherwords, before the magnetic disc pack 10 is inserted into a pack holderto be described later, the shutter 20 closes the window portion 18 toprotect the magnetic disc 12 against dust and, after the magnetic discppack 10 is inserted into the pack holder, the shutter 20 is secured by aclaw provided in the pack holder and is moved in a downward direction inFIG. 15 to open the window 18.

As shown in FIG. 18, the shutter 20 is bent formed in a substatinallyU-like shape and is slidably mounted to the magnetic disc pack 10 fromone edge (in FIG. 16, from the right edge of the magnetic disc pack 10in such a manner that the magnetic disc pack 10 is put between the twoflat surfaces of the shutter 20.

In the shutter 20, as shown in FIGS. 18 and 19, there are formed bores20 A and 20 B. The bore 20 A is provided with a projection 20 C which isformed in a folded manner. The projection 20 C can be brought intoenagagement with a recessed portin 21 A (which is shown in FIG. 16)formed in a lock member 21 to lock the shutter 20 in an immovablemanner.

Further, the magnetic disc pack 10 is formed with positioning bores 10A, 10 B which are used to position the magnetic disc pack 10 in aposition for magnetic recording or reproduction. The structure of theabove-mentioned magnetic disc pack is defined by a unified standard.

Referring now to FIG. 1, there is shown an exploded perspective view ofan example of a magnetic recording/reproducing apparatus to which thepresent invention is applied. The illustrated magneticrecording/reproducing apparatus comprises, as its major components, asupport plate 100, a pack holder 200, a side plate 300, a right-sideframe 400, a left-side frame 500, a main arm 600, a regulation plateholder 700, and a cover opening/closing mechanism 800.

Referring at first to the internal structure of the support plate, thesupport plate 100 is equipped with a motor 102 which is used to drivethe magnetic disc. The magnetic disc driving motor 102 has a drive shaft104 which can be fitted into the central bore 15 in the center core 14of the magnetic disc pack 10 shown in FIG. 16 to rotate the magneticdisc 12 at a given number of rotations within the magnetic disc pack 10.

Also, in the support plate 100, there are provided a magnetic head whichis not shown, a head carriage to which the magnetic head is mounted, anda feed motor which is used to move the head carriage by means of a leadscrew. If the feed motor is rotated every given number of rotations,then the rotational movement of the feed motor is transmitted to thelead screw through a reduction gear. By means of the rotational movementof the lead screw, the head carriage is then moved every given pitch inthe axial direction of the lead screw and at the same time the magnetichead is also moved in the radial direction of the magnetic disc 12. Thatis, the magnetic head is moved in this manner to thereby magneticallyrecord still image information or the like onto the magnetic disc 12,for each of tracks provided on the magnetic disc 12 or reproducetherefrom. In FIG. 1, reference numerals 106, 108 respectively designatepositioning pins used to position the magnetic disc pack, over whichpositioning pins 106, 108 the positioning bores 10 A, 10 B (FIG. 16) areto be fitted, respectively. Also, numerals 110, 112 respectivelydesignate pins used to position the height of a regulation plate 702,over which pins 110, 112 are fitted bored pins 704, 706 mounted to theregulation holder 700, respectively.

In the pack holder 200, there are provided guide pieces 202, 204, 206forming a guide groove which is used to guide and support the side (theright side in FIG. 16) of the magnetic disc pack 10 in which the shutter20 is provided, a groove 210 into which a shutter opening member 252 anda claw 254 a of a shutter closing member 254 can be inserted, and aslider surface 220 engageable with a lever 802 for opening or closing asecond cover 808. Also, there is interposed a spring 230 between a bore228 c formed in a pop-up member 228 and a bore 216 on the side of thepack holder, and, similarly, there is interposed a spring 234 between abore 232 a formed in a pre-lock lever 232 and a hook 218 on the side ofthe pack holder. The above-mentioned pre-lock lever 232 is rotatablymounted to the pack holder 200 by means of pins 236, 238. Further, inthe pack holder 200, there is provided a leaf switch 240 which is usedto confirm that the magnetic disc pack has been inserted.

The above-mentioned pack holder 200 is mounted to the side plate 300 bypins 306, 308 by means of a spacer 302, 304, and elongated bores 250 a,250 b formed in a vertical slide plate 250 to be discussed later.

The above-mentioned vertical slide plate 250 is guided by fourprojections 320 a, 320 b, 320 c, 320 d respectively formed in the sideplate 300 in such a manner that it is free to slide in a verticaldirection along the side plate 300. Also, the vertical slide plate 250is provided with a bent formed shutter opening member 252 and a shutterclosing member 254 is mounted to the vertical slide plate 250 by pins256, 258.

On the other hand, between the pack holder 200 and two spacers 302, 304there is interposed the pop-up member 228 which is free to slidelongitudinally (that is, in the magnetic disc pack insertion/dischargedirection) along the pack holder 200. Also, between the side plate 300and two pins 306, 308 there is interposed a longitudinal slide plate 310which is guided by four projections 312 a, 312 b, 312 c, 312 drespectively formed in the side plate 300 such that the longitudinalslide plate 310 is free to slide in a longitudinal, that is,back-and-forth direction along the side plate 300. Further, in the sideplate 300 there is arranged a lock removing spring 316 by means of a pin314, and in the longitudinal slide plate 310 there is provided a camfollower 318.

In the frame 400 shown right in FIG. 1, there are projectingly providedthree rotary shafts 402, 404, 406, and a double cam 408, a gear 410 anda gear 412 are mounted to the rotary shafts, respectively. Also, betweenthe frame 400 and the side plate 300 there is interposed a motor 414 forpower loading. The motor 414 has a drive shaft (not shown, but directeddownward) which is provided with a worm gear. The worm gear is adaptedto engage with the smaller gear 412 a of the gear 412, the larger gear412 b of the gear 412 engages with the larger gear 410 a of the gear410, and the smaller gear 410 b of the gear 410 engages with a gear 408a formed on the circumferential surface of the double cam 408. Thedouble cam 408 is formed with a spirally-shaped cam groove 416 on onesurface thereof which is shown, into which cam groove 416 the camfollower 318 provided in the longitudinal plate can be fitted, which thedouble cam 408 is formed with a sprially-shaped cam groove (not shown)on the other surface thereof, into which cam groove a cam follower 604provided in the right arm 602 of the main arm 600 can be fitted.

In the frame 500 shown left in FIG. 1, there is arranged a sub-arm 502by means of a pin 504 such that the sub-arm 502 is free to rotate, andthere is arranged a member 506 which is used to regulate the position ofthe left side face of the magnetic disc pack 10 when the magnetic discpack 10 is inserted into the pack holder.

Now, in the main arm 600, there is arranged a shaft 620 which isprovided with three springs 622, 624, 626 and the left end of the shaft620 is journaled to a bore 508 formed in the left-situated frame 500.Also, on the base portion of the right arm 602 of the main arm 600,there is projected a shaft (not shown) which is journaled to a bore 420formed in the right frame 400. Due to this, the main arm 600 is free torotate with respect to the right and left frames.

Also, in the leading end of the right arm 602 of the main arm 600, asdescribed before, there is provided the cam follower 604; in the leftarm 602 thereof, there are provided a support portion 608 used tosupport the left side portion of the magnetic disc pack 10, and asupport portion 609 which is bent formed to support the sub-arm 502;and, in the central portion of the main arm 600 there are provided threecenter core push portions 610, 612, 614.

Referring then to the regulation plate holder 700, the holder 700 isprovided with a regulation plate 702 in the lower surface thereof, and aP.G sensor 708 in the upper surface thereof. The P.G sensor 708 isarranged such that a detection portion 708 a thereof stands opposite toa bore 710 formed in the regulation plate holder 708, and the sensor isadapted to generate a pulse signal each time a magnetic generationportion 26 (FIG. 16) provided on the upper surface of the center core 14is positioned in the above-mentioned bore 710. The pulse signal is usedto detect the rotational phase of the magnetic disc 12. Also, a heightpositioning pin 714 for the regulation plate 702 to be abutted againstthe drive shaft 104 of the motor 102 of the regulation plate holder 700is screwed into a position 712 which stands opposite to the drive shaft104 of the motor 102.

The above-mentioned regulation plate holder 700 is held alwayshorizontally by means of a three-point support method using the twosupport portions 616, 618 in the main arm 600 and the support portion502 a in the sub-arm 502. Also, the regulation plate holder 700 isenergized downward by the three springs 622, 624, 626 provided in theshaft 620 to be mounted to the main arm 600.

In addition, in FIG. 1, there is shown a cover opening/closing mechanism800 which is mainly composed of a lever 802, a first cover 804, a frontframe 806, a second cover 808, and a front panel 810. The lever 802 ismounted in a freely rotatable manner to the member 506 and the sideplate 300 respectively by means of pins 812 and 814, and at the sametime it is energized in a counterclockwise direction by a spring 816.Further, there is provided a bent piece 818 in the lever 802 and thus,when the bent piece 818 is brought into contact with the slide surface220 of the pack holder 200, then the above-mentioned counterclockwiserotational movement of the lever 802 is regulated.

The first cover 804 is rotatably mounted to the right and left frames400, 500 by means of a shaft 820 and also is energized counterclockwiseby a spring 822 provided on the shaft 820 such that it is normally incontact with the front frame 806 interposed between the right and leftframes 400 and 500. In the second cover 808, there are provided pins 824and 826 which are in engagement with elongated bores 828 and 830 formedin the lever 802 by means of the front frame 806, respectively.

Next, description will be given below of the operation of the respectiveparts of the magnetic recording/reproducing apparatus constructed in theabove-mentioned manner.

In FIG. 2(a), there is shown a state before the magnetic disc pack 10 ispre-locked. The pre-lock mechanism is mainly composed of the pop-upmember 228 and the pre-lock lever 232. The pop-up member 228 is arrangedsuch that it is free to slide back and forth, or, in a longitudinaldirection with respect to the pack holder 200, and the pre-lock lever232 is arranged such that it is free to rotate with respect to the packholder 200.

Although the pre-lock lever 232 is energized counterclockwise by thespring 234, when the contact surface 232 b thereof is brought intocontact with the contact piece 228 b of the pop-up member 228, thepre-lock lever 232 is prevented from rotating further. Now, FIG. 2(b) isa section view taken along the line A--A in FIG. 2(a).

In this state, the magnetic disc pack 10 is inserted into the packholder to bring the front surface of the magnetic disc pack into contactwith the engagement portion 228a of the pop-up member 228. After then,if the magnetic disc pack 10 is inserted further, then the pop-up member228, together with the magnetic disc pack 10, is advanced against theenergization force of the spring 230. And, when the pop-up member 228 isadvanced a given distance so that the contact surface 228 is advanced agiven distance so that the contact surface 228 b thereof moves from thecontact surface 232b of the pre-lock lever 232 to the contact surface232c thereof then as shown in FIG. 3(a), the pre-lock lever 232 isrotated counterclockwise by an amount corresponding to the difference inlevel between the two contact surfaces. This rotational movement of thepre-lock lever 232 causes the engagement portion 232 d provided in theleading end of the pre-lock lever 232 to move downward into engagementwith the positioning bore 10 A previously formed in the magnetic discpack 10. Now, FIG. 3(b) is a plan view of FIG. 3 (a), illustrating astate in which the projection portion 232 d of the pre-lock lever 232 isin engagement with the positioning bore 32 in the magnetic disc pack 10.The foregoing operations complete the pre-locking of the magnetic discpack.

In FIG. 4, there is shown a state in which the magnetic disc pack 10 isloaded in an advancing direction after it is pre-locked. During thisadvancement, the bent portion 232 f of the pre-lock lever 232 gets overthe lock removing spring 316 provided in the lower portion of the sideplate 300 while the bent portion 232 f pushes against the spring.

In FIG. 5, there is shown a state in which the magnetic disc pack 10 isfurther advanced and after then it is lowered down a given distance. InFIG. 5, a position illustrated by a two-dot chained line B shows theposition of the magnetic disc pack 10 when it is initially pre-locked.

Next, we will describe below how to remove the pre-locking. Referring toFIG. 6, there is shown a state in which the magnetic disc pack 10together with the pre-lock mechanism are retreating, that is, moving ina right direction during the unloading of the magnetic disc pack. Duringthis retreat, the bent portion 232 f of the pre-lock lever 232 isbrought into contact with the lock removing spring 316 to thereby rotatethe pre-lock lever 232 clockwise until the lever to which the spring 234is mounted is brought into contact with the circumferential surface ofthe spacer 302. As a result of this, the pre-locking by the pre-locklever 232 is removed and the engagement between the pop-up member 228and the pre-lock lever 232 is also removed, so that the pop-up member228 can be operated by the energization force of the spring 230.

As shown in FIG. 7, when the above-mentioned unloading is carried outfurther, the bent portion 232 f of the pre-lock lever 232 pushes andbends the lock removing spring 316 to get it over. As a result of this,the pre-lock mechanism returns to the state shown in FIG. 2.

Next, description will be given below of the operation of the setmembers (such as the main arm 600, regulation plate holder 700 and thelike). In FIG. 1, if the double cam 408 is rotated in the driection ofan arrow A, then the main arm 600, the cam follower 604 of which isfitted into the other cam groove (not shown) of the double cam 408, isrotated clockwise. As a result of this, the regulation plate holder 700,which is supported horizontally by three points, that is, the twosupport portions 616, 618 of the main arm 600 and the support portion502 a of the sub-arm 502 with one end thereof being guided into theguide bore 500 a of the left frame 500, is caused to move down to apredetermined height while maintaining its horizontal state. And, whenthe main arm 600 is rotated a given amount, then the three center corepush portions 610, 612, 614 of the main arm 600 push against the centercore 14 of the magnetic disc 12 to thereby bring the central bore 15 ofthe center core 14 into firm engagement with the drive shaft 104.

Now, description will be given below of the pack holder movingmechanism.

In FIG. 8, during the loading of the magnetic disc pack, a driving forceis trasmitted from the motor 414 through the gears 412, 410 to thedouble cam 408, so that the double cam 408 is rotated in the directionof the arrow A, as shown in FIG. 8(a). When the double cam 408 isrotated in the arrow A direction, then the longituidnal slide plate 310,the cam follower 318 of which is fitted into the cam groove 416 in thedouble cam 408, is caused to advance, with the result that the pins 306,308 are moved along substantially L-shaped bores 300a, 300b formed inthe side plate 300 by oblique bores 310a, 310b formed in thelongitudinal slide plate 310.

In other words, when the double cam 408 is rotated about 180° from itsinitial state shown in FIG. 8(a), then the pack holder 200 is moved tothe end of advancement, as shown in FIG. 8(b). Then, when the double cam408 is rotated about 180° further, then the pack holder 200 is moveddown to the end of lowering, as shown in FIG. 8(c).

The double cam is also formed with two different cam grooves in order toprevent the above-mentioned main arm 600 against rotation while the packholder 200 is advancing, to allow the main arm 600 to rotatesynchronously with the pack holder 200 while the pack holder 200 islowering, and to allow only the main arm 600 to rotate for center corepushing after the lowering of the pack holder 200 is completed.

Next, description will be given of the mechanism for opening or closingthe shutter in the magnetic disc pack. As shown in FIG. 1 and FIG. 8,the shutter opening/closing mechanism is mainly composed of the verticalslide plate 250, shutter opening meber 252 and shutter closing member254.

The vertical slide plate 250, as shown in FIG. 1, is guided by the fourprojections 320a through 320d provided in the side plate 300 and is freeto slide along the side plate 300 only in the vertical direction. Thatis, as shown in FIG. 8, the pack holder 200 can be moved along thesubstantially L-shaped bores 300A, 300B formed in the side plate 300,while vertical slide plate 250 can be moved together with the packholder 200 only in a direction perpendicular to the direction ofinsertion of the magnetic disc pack (in FIG. 8, in a verticaldirection). In the vertical slide plate 250, there are formed twoelongaged bores 250a, 250b in order to prevent interference with theguide pins 306, 308 when the pack holder 200 is moved in theinsertion/discharge direction of the magnetic disc pack (in FIG. 8, inthe right and left direction).

Also, as shown in FIG. 1, the above-mentioned vertical slide plate 250is provided with the shutter opening member 252 which formed by folding,and also the shutter closing member 254 is mounted to the vertical slideplate 250 by means of the pins 256, 258. Further, the shutter closingmember 254 is formed of a resilient member and, therefore, if the claw254a of the shutter closing member 254 that is engageable with the bore20A in the shutter side face is pushed against the resiliency thereof,then the claw 254a is caused to retreat, for example, as shown in FIG.10. In addition, the shutter opening member 252 and the claw 254a of theshutter closing member 254 are arranged such that they can be projectedinto the insertion area of the magnetic disc pack 10 provided in thepack holder 200, as shown in FIG. 8.

Next, description will be given below of the operation of theabove-mentioned shutter operning/closing mechanism with reference toFIGS. 9 through 14.

Referring to FIG. 9, there is shown a state in which the magnetic discpack 10 is not yet inserted into the pack holder 200. If the magneticdisc pack 10 is inserted from the above state into the pack holder 200as shown by the arrow A, then, as shown in FIG. 10, the shutter 20 ofthe magnetic disc pack 10 is firstly caused to push the shutter closingmember 254 against the resiliency thereof and get over the claw 254athereof.

Also, when the magnetic disc pack 10 is inserted into the pack holder200, then the leading end of the shutter 20 is brought into contact withthe shutter opening member 252, as shown in FIG. 11. As a result ofthis, the shutter opening member 252 removes the locking of the shutter20 by the lock member 21 (FIG. 16). Also, due to the fact that the bore20B formed in the shutter side face is caused to move to the position onthe claw 254a of the shutter closing member 254, the claw 254a isbrought into engagement with this bore 20B and at the same time theshutter closing member 254 is caused to return to its initial positiondue to the resiliency thereof.

If the magnetic disc pack 10 is inserted from the state shown in FIG. 11further into the pack holder, then shutter 20 can be opened by theshutter opening member 252, as shown in FIG. 12. The state shown in FIG.12 illustrates a state in which the magnetic disc pack 10 has beeninserted up to a given position (that is, the position as shown in FIG.3 where the magnetic disc pack 10 is pre-locked). Also, as shown in FIG.12, the shutter 20 is not yet opened fully.

When the magnetic disc pack 10 is pre-locked in the pack holder 200 asdescribed before, then the loading operation is started, as shown inFIG. 8. Then, if the pack holder 200 advances from the position thereofshown in FIG. 8(a) up to the position thereof shown in FIG. 8(b), thenthe magnetic disc pack 10 also advances together with the pack holder200. On the other hand, the shutter opening/closing mechanism providedin the vertical slide plate 250 is not moved due to the fact that themovement thereof in the magnetic disc pack insertion direction isprevented, with the result that due to the relative movement between thevertical slide plate 250 and the magnetic disc pack 10 the shutter 20can be opened until it opened fully, as shown in FIG. 13. During themovements of the pack holder 200 from FIG. 8(b) to FIG. 8(c), thevertical slide plate 250 follows after the pack holder 200, so that thestate shown in FIG. 13 can be maintained.

Next, we will describe how to close the shutter 20 of the magnetic discpack 10. In this case, at first, if the pack holder 200 is moved in themagnetic disc pack discharge direction from the state shown in FIG. 8(b)to the state shown in FIG. 8(a) during the unloading of the magneticdisc pack 10, then the shutter 20 is closed to the above-mentioned stateshown in FIG. 12 and also, during the movement of the pack holder in theabove-mentioned discharge direction, the pre-locking of the magneticdisc pack 10 is removed as shown in FIG. 6 so that the magnetic discpack 10 can be moved further in the discharge direction, whereby theshutter 20 can be further closed. After then, if the magnetic disc pack10 is pulled in the discharge direction (in FIG. 14, in the rightdirection), then the shutter 20 can be locked again by the lock member21.

After the shutter 20 is locked, if the magnetic disc pack 10 is pulledfurther in the discharge direction, then, as shown in FIG. 14, the claw254 a of the shutter closing member 254 is caused to retreat against theresiliency of the shutter closing member 254 because the bore 20B in theshutter 20 is moved along the tapered surface of the claw 254a, so thatthe claw 254a can be disengaged from the bore 20B in the shutter 20.

Although in the illustrated embodiment the shutter closing member isformed of a resilient member, the present invention is not limited tothis, but, alternatively, a shutter closing member may be rotatablyprovided in a vertical slide plate such that the claw of the shutterclosing member may be energized by a spring so as to project into aninsertion area for a magnetic disc pack provided in a pack holder.

Next, description will be given below of the mechanism for opening orclosing the cover. In FIG. 15, the magnetic disc pack 10 is guidedthrough the insertion opening 832 of the fron panel 810, pushed againstthe first cover 804 and inserted into the pack holder 200, when themagnetic disc pack 10 is pre-locked to the pack holder 200 by thepre-lock mechanism, as shown in FIG. 3. After then, as the pack holder200 is lowered down by the pack holder 200 moving mechanism (FIG. 8),the slide surface 220 of the pack holder 200 is also lowered down, sothat the lever 802, with its bent piece 818 in contact with the slidesurface 220, is rotated counterclockwise to thereby move the secondcover 808 upwardly. As a result of this, the insertion opening 832 isclosed by the second cover 808 to prevent the double insertion of themagnetic disc pack.

As has been described hereinbefore, in the magnetic disc pack loadingmechanism according to the present invention, due to the fact that,during loading, the magnetic disc pack can be held positively in thepack holder, and also that the magnetic disc pack can be pre-locked whenit is inserted a given amount, there is eliminated the inconvenience tocontinue pushing the magnetic disc pack until the beginning of theloading as in the prior art.

Also, according to the invention, since the shutter of the magnetic discpack is adapted such that it can be fully opened by use of the loadingoperation in the insertion direction of the magnetic disc pack, theshutter opening member, shutter closing member and the like can bedisposed in positions comparatively deeper from the magnetic disc packinsertion opening in the front panel, which can provide sufficient spaceinside of the front panel. As a result of this, there can be eliminatedthe inconvenience that the inner cover mounted rotatably inside of thefront panel and the shutter closing member may interfere with eachother, as in the prior art.

It should be understood, however, that there is no intention to limitthe invention to the specific forms disclosed, but on the contrary, theinvention is to cover all modifications, alternate constructions andequivalents falling within the spirit and scope of the invention asexpressed in the appended claims.

What is claimed is:
 1. A magnetic disc pack loading mechanism forpositioning a magnetic disc pack in a recording or reproducing positionby moving a pack holder containing said magnetic disc pack therein inthe same direction with the direction to insert said magnetic disc packinto said pack holder and thereafter moving said pack holder in thelongitudinal direction of a rotary drive shaft perpendicular to saidmagnetic disc pack insertion direction, said magnetic disc pack loadingmechanism comprising:a pop-up member disposed in said pack holder in amanner to be free to advance or retreat and provided in a tip of saidpop-up member with an engagement portion located in an area forinsertion of said magnetic disc pack within said pack holder, saidpop-up member being adapted to advance against the energization force ofa spring acting in the discharge direction f said magnetic disc packwith said engagement portion thereof engaged with the leading end ofsaid magnetic disc pack when said magnetic disc pack is inserted intosaid pack holder with a given pushing force; a pre-lock lever disposedrotatably in said pack holder and provided in the tip of said pop-upmember with an engagement portion being energized by a spring in adirection for engagement with said magnetic disc pack, said pre-locklever being adapted to be able to provisionally lock said magnetic discpack within said pack holder with said engagement portion thereofengaged with said magnetic disc pack when said pre-lock lever is rotateda given amount; and, a cam mechanism including a cam portion provided inone of said pop-up member and said pre-lock lever and a cam followerportion in the other, said cam mechanism being adapted to prevent saidpre-lock lever against rotation before said pop-up member advances agiven distance and to allow said pre-lock lever to rotate in saidengagement direction after said pop-up member advances said givendistance.
 2. A magnetic disc pack loading mechanism as set forth inclaim 1, wherein said pop-up member is adapted such that the movementthereof in the discharge direction of said magnetic disc pack isrestricted by said cam mechanism when said pre-lock lever is rotated topre-lock said magnetic disc pack.
 3. A magnetic disc pack loadingmechanism as set forth in claim 1, wherein said engagement portionprovided in the leading end of said pre-lock lever is to be fitted intoa positioning bore previously formed in said magnetic disc pack forpositioning said magnetic disc pack.
 4. A magnetic disc pack loadingmechanism as set forth in claim 1, wherein there is provided on a fixedposition of a magnetic recoding/reproducing apparatus a lock removingspring adapted such that, when loading said magnetic disc pack, it isnot brought into engagement with said pre-lock lever while said packholder is moving in the same direction with the insertion direction ofsaid magnetic disc pack, but, when unloading said magnetic disc pack, itis brought into engagement with said pre-lock lever while said packholder is moving in a direction opposite to said insertion direction ofsaid magnetic disc pack to rotate said pre-lock lever in a directionopposite to the rotational direction thereof during said pre-lockingoperation.